As I can tell from my own experience: I have been beat on my butt about 5 times in my life (fortunately it has always been only one spank, I never got put over a lap). And I was a very obedient child, but whenever I did something not exactly right (even unintentionally) I feared my mom might get angry and beat me. The fear was really strong. Even now, at age of 19, I deep in heart fear it, though I last got a spank about 10 years ago.

I guess spanking do teach children dispicline and respect for their parents, but it is at the cost of their mental condition sometimes (when they are very vulnerable, like I was).I guess I wouldn't be that abedient if I never got hit. A little fear can do good, but only a little.